OXIDATION RATES OF COMMON ORGANIC-COMPOUNDS IN SUPERCRITICAL WATER

Supercritical water oxidation is a rapidly emerging thermal waste-proc essing technology with potential as a hazardous-waste-treatment method for a variety of industrial chemicals ranging from common organic sol vents to complex industrial formulations, An important design consider ation in the development of supercritical water oxidation is the optim ization of reactor operating temperature and feed preheat temperatures . In this paper, the temperature dependence of the oxidation in superc ritical water of seven common organic compounds is examined over a tem perature range of 430-585 degrees C and reaction times ranging from 7 to 30 s at 27.6 MPa (4000 psi). The reactants are examined at approxim ate concentrations of 0.4 wt.% at conversion efficiencies from 50% to > 99.9%, The materials examined were methanol, phenol, methyl ethyl ke tone, ethylene glycol, acetic acid, methylene chloride, and 1,1,1-tric hloroethane. The conversion of these compounds was monitored using tot al organic carbon and gas chromatography on liquid effluent samples. T he results indicate that for most compounds, temperatures over 550 deg rees C and residence times near 20 s afford conversion efficiencies of greater than 99.95% based on total organic carbon. (C) 1998 Elsevier Science B.V.